The present invention relates to a telephone equipment including a main telephone and cordless handsets, and particularly, to the telephone equipment in which an extension communication (i.e., a communication between the cordless handsets) can be performed.
Conventionally, telephone equipment having a function of the extension telephone communication has been known. The extension communication is performed between the cordless handsets via the main phone. The extension communication is realized, for example, by use of a transceiving function. In the extension communication using the transceiving function, when one of the cordless handsets operates in a transmitting mode, the other operates in a receiving mode. The transmitting mode and the receiving mode are switched by an operation at the cordless handsets, thereby a two-way (alternating) communication is realized. In such telephone equipment, when an outside line call is received and the call is transferred from one cordless handset to another, the outside line call is temporarily held, and the extension communication may be made between the cordless handsets.
In the conventional telephone equipment, when the holding state of the outside line call continues for a predetermined period, the call as held is forcibly connected to one of the cordless handsets, or the outside line call is forcibly cut.
When the outside line call is forcibly connected to one of the cordless handsets, a user of the cordless handset feels that the line is connected to the outside line call abruptly. In such a case, the user may confuse as he/she may not recognize whether the outstanding call is the outside line call or the extension call. When the outside line call is forcibly disconnected, a caller of the outside line call should make a call again, which gives the caller displeasure.
Japanese Patent No. 2590104 discloses telephone equipment which keeps the holding status of the outside line call even when the extension call lasts for a relatively long period. In this telephone equipment, in order to keep the holding state of the outside line call for a long period, a self-maintenance operation is performed by a power supply path for maintaining the holding state, thereby the holding state is maintained even if the extension call last relatively long.
According to the telephone equipment disclosed in the above-indicated patent, when the extension communication lasts for a relatively long period, the caller of the outside line call may be kept waiting for a long period, and may have an unpleasing feeling.